The run() cleanup block was guarded by `except (ConnectionError, OSError):`,
so exits via asyncio.CancelledError or any other exception type skipped
cleanup. Result: `_reader_process` stays pinned to the dead reader and
`_get_reader()` returns None for every subsequent client — the silent-proxy
symptom described in #2344.
Convert the except block to try/finally so cleanup always runs, regardless
of how `_process()` exits. Also:
- catch asyncio.CancelledError + generic Exception (with log.exception) so
unexpected failures don't swallow the cleanup
- reset `_current_read = None` after cancellation
- use `dict.pop(..., None)` instead of `del` to avoid KeyError races if
the broadcast loop's timeout handler already removed the entry
Triggering pattern observed in practice: a diagnostic tool opens a console,
sends a few commands, and closes abruptly (e.g. from a test harness or
orchestration script that cancels its Task). If the `_process()` task was
awaiting on one of the `network_read` / `reader_read` futures at the time
of cancellation, the CancelledError propagates up through `run()` and
bypasses the ConnectionError-only except clause. The proxy accepts future
connections (the listen socket is still alive) but never forwards any data
because `_reader_process` never got reset.
Validated against gns3/gns3-server:latest (2.2.56.1) running a 10-scenario
sequential regression batch that previously hung reliably on the 4th
sp_v1 / L3VPN scenario and now completes cleanly across all 10.
- Catch OSError alongside ConnectionError in connection processing to handle more network errors
- Move client_info retrieval inside try block to prevent AttributeError on failed connections
- Replace bare except with specific exceptions (OSError, ConnectionError, asyncio.TimeoutError)
- Improve error logging to include specific exception details and client information
